{
  "id": "tdigest.cdf",
  "title": "TDIGEST.CDF",
  "url": "https://redis.io/docs/latest/commands/tdigest.cdf/",
  "summary": "Returns, for each input value, an estimation of the floating-point fraction of (observations smaller than the given value + half the observations equal to the given value)",
  "tags": [
    "docs",
    "develop",
    "stack",
    "oss",
    "rs",
    "rc",
    "oss",
    "kubernetes",
    "clients"
  ],
  "last_updated": "2026-04-09T10:29:34-04:00",
  "page_type": "content",
  "content_hash": "39eb042967e72d146a50efbfd616134680e005a227dfd857ad07f0c4aff1cbad",
  "sections": [
    {
      "id": "overview",
      "title": "Overview",
      "role": "overview",
      "text": "Returns, for each input value, an estimation of the floating-point fraction of (_observations smaller than the given value_ + _half the observations equal to the given value_).\nMultiple fractions can be retrieved in a single call."
    },
    {
      "id": "required-arguments",
      "title": "Required arguments",
      "role": "content",
      "text": "<details open><summary><code>key</code></summary>\n\nis the key name for an existing t-digest sketch.\n</details>\n\n<details open><summary><code>value</code></summary>\n\nare the values for which the CDF (Cumulative Distribution Function) should be retrieved.\n</details>"
    },
    {
      "id": "examples",
      "title": "Examples",
      "role": "example",
      "text": "redis> TDIGEST.CREATE t COMPRESSION 1000\nOK\nredis> TDIGEST.ADD t 1 2 2 3 3 3 4 4 4 4 5 5 5 5 5\nOK\nredis> TDIGEST.CDF t 0 1 2 3 4 5 6\n1) \"0\"\n2) \"0.033333333333333333\"\n3) \"0.13333333333333333\"\n4) \"0.29999999999999999\"\n5) \"0.53333333333333333\"\n6) \"0.83333333333333337\"\n7) \"1\""
    },
    {
      "id": "redis-software-and-redis-cloud-compatibility",
      "title": "Redis Software and Redis Cloud compatibility",
      "role": "content",
      "text": "| Redis<br />Software | Redis<br />Cloud | <span style=\"min-width: 9em; display: table-cell\">Notes</span> |\n|:----------------------|:-----------------|:------|\n| <span title=\"Supported\">&#x2705; Supported</span><br /> | <span title=\"Supported\">&#x2705; Flexible & Annual</span><br /><span title=\"Supported\">&#x2705; Free & Fixed</nobr></span> |  |"
    },
    {
      "id": "return-information",
      "title": "Return information",
      "role": "returns",
      "text": "**RESP2:**\n\nOne of the following:\n\n* [Array]() of [bulk string replies]() as floating-points, populated with fraction_1, fraction_2, ..., fraction_N.\nAll values are `nan` if the given sketch is empty.\n* [Simple error reply]() in these cases: the given key does not exist or is of an incorrect type, value parsing errors, or an incorrect number of arguments.\n\n**RESP3:**\n\nOne of the following:\n\n* [Array]() of [doubles]() populated with fraction_1, fraction_2, ..., fraction_N.\nAll values are `nan` if the given sketch is empty.\n* [Simple error reply]() in these cases: the given key does not exist or is of an incorrect type, value parsing errors, or an incorrect number of arguments."
    }
  ],
  "examples": []
}